A lithium-ion secondary battery with high capacity and excellent charge and discharge cycle performance is provided. A secondary battery with high capacity is provided. A secondary battery with excellent charge and discharge characteristics is provided. A secondary battery in which a reduction in capacity is inhibited even when a state being charged with a high voltage is held for a long time is provided. A secondary battery includes a positive electrode, a negative electrode, and an electrolyte, and the amount of moisture in the electrolyte is less than 1000 ppm.